The invention relates to an image processing system for still images.
When dealing with still images from a relatively noisy source (e.g., scanning electron microscope) there is a requirement to reduce such noise efficiently to provide a usable image. It is also desirable to filter the image to enhance a characteristic of the image, such as edges therein.
It has been the practice in the past to employ slow scan techniques with a long persistence screen to generate a usable image with reduced visible noise.
This technique has the disadvantage of producing a bright image at the appropriate scanning line, whilst the earlier lines are less bright and fade in dependence on the degree of persistence. An alternative solution has required the production of photographs by a camera in contact with the screen. Whilst this gives better results the speed and flexibility of such a system is restricted.
The Applicants have recently become aware of UK Patent Specification No. 2122050A in the name of N. V. Philips, Gloeilampenfabriken and published Jan. 4, 1984.